Dick de Zwart

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Biological sensors are becoming more important to monitor the quality of the aquatic environment. In this paper the valve movement response of freshwater (Dreissena polymorpha) and marine (Mytilus edulis) mussels is presented as a tool in monitoring studies. Examples of various methods for data storage and data treatment are presented, elucidating easier(More)
Organic concentrates of the River Rhine water were tested for toxicity with a 15 minute test (MicrotoxTM) on luminescent bacteria (Photobacterium phosphoreum, Bacteria). A total number of 18 stations in the Dutch lower Rhine area were sampled five times with an interval of one month (April 1988–August 1988), whereas two stations located the most apart(More)
The temporal and spatial dynamics of phytoplankton in the River Meuse and a number of physical and chemical parameters were analyzed to gain insight into the pollution level in the river affecting the phytoplankton community. During 1993, samples were taken every two months at eight stations along the River Meuse for physical, chemical and biological(More)
The EU Water Framework Directive (WFD), establishing stringent quality objectives for European basins in the next years, prompts for the development of new tools to evaluate and improve the ecological status over European rivers. The present paper will provide an overview of the main activities carried out in the DECIS subproject within MODELKEY, an(More)
Three-stage aquatic microcosms have been employed to investigate the long-term effects of subtle temperature rises. The type of microcosm used consists of three seperate aquaria, each representing one of the following trophic levels: autotrophs, herbivores and decomposers. The subsystems are interconnected by a pump-driven circulation flow. During a(More)
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